Problem: Given a string of length n s = s1, s2,…, sn and m queries. Each query qk (1 ≤ k ≤ m) is one of four types, "L ++", "L-", "R ++", "R-", and l [for the kth query qk. k] and r [k] are defined below.

* L ++: l [k] = l [k-1] + 1, r [k] = r [k-1]

* L-: l [k] = l [k-1] -1, r [k] = r [k-1]

* R ++: l [k] = l [k-1], r [k] = r [k-1] +1

* R-: l [k] = l [k-1], r [k] = r [k-1] -1




However, l [0] = r [0] = 1.

At this time, how many kinds of character strings are created for m substrings sl [k], sl [k] + 1,…, sr [k] -1, sr [k] (1 ≤ k ≤ m). Answer if you can.

Constraints

* The string s consists of a lowercase alphabet

* 1 ≤ n ≤ 3 x 105

* 1 ≤ m ≤ 3 × 105

* qk (1 ≤ k ≤ m) is one of "L ++", "L-", "R ++", "R-"

* 1 ≤ l [k] ≤ r [k] ≤ n (1 ≤ k ≤ m)

Input

Input is given in the following format

> n m
> s
> q1
> q2
>…
> qm
>

Output

Output the solution of the problem on one line

Examples

Input

5 4
abcde
R++
R++
L++
L--


Output

3


Input

4 6
abab
R++
L++
R++
L++
R++
L++


Output

4


Input

10 13
aacacbabac
R++
R++
L++
R++
R++
L++
L++
R++
R++
L--
L--
R--
R--


Output

11

Solution (in CPP):

Solution:
#include <bits/stdc++.h>

using namespace std;

#define SZ(x) (int)(x.size())

using ll = long long;
using ld = long double;
using P = pair<int, int>;
using vi = vector<int>;
using vvi = vector<vector<int>>;
using vll = vector<ll>;
using vvll = vector<vector<ll>>;
const double eps = 1e-10;
const int MOD = 1000000007;
const int INF = 1000000000;
const ll LINF = 1ll<<50;

template<typename T>
void printv(const vector<T>& s) {
  for(int i=0;i<(int)(s.size());++i) {
    cout << s[i];
    if(i == (int)(s.size())-1) cout << endl;
    else cout << " ";
  }
}

const int MAX = 500000, MS = 2;
const long long mod[] = {999999937LL, 1000000007LL}, base = 9973;
struct rolling_hash {
    int n;
    vector<long long> hs[MS], pw[MS];
    rolling_hash(){}
    rolling_hash(const string &s) {
        n = s.size();
        for (int i = 0; i < MS; i++) {
            hs[i].assign(n+1,0);
            pw[i].assign(n+1,0);
            hs[i][0] = 0;
            pw[i][0] = 1;
            for (int j = 0; j < n; j++) {
                pw[i][j+1] = pw[i][j]*base%mod[i];
                hs[i][j+1] = (hs[i][j]*base+s[j])%mod[i];
            }
        }
    }

    long long hash(int l, int r, int i) { return ((hs[i][r]-hs[i][l]*pw[i][r-l])%mod[i]+mod[i])%mod[i]; }

    bool match(int l1, int r1, int l2, int r2) {
        bool ret = 1;
        for (int i = 0; i < MS; i++) ret &= hash(l1,r1,i)==hash(l2,r2,i);
        return ret;
    }

    bool match(int l, int r, long long h[]) {
        bool ret = 1;
        for (int i = 0; i < MS; i++) ret &= hash(l,r,i)==h[i];
        return ret;
    }
};

struct rolling_hash64 {
    int n;
    vector<long long> hs, pw;
    rolling_hash64(){}
    rolling_hash64(const string &s) {
        n = s.size();
        hs.assign(n+1,0);
        pw.assign(n+1,0);
        pw[0] = 1;
        for (int i = 0; i < n; i++) {
            hs[i+1] = hs[i]*base+s[i];
            pw[i+1] = pw[i]*base;
        }
    }

    long long hash(int l, int r) { return hs[r]-hs[l]*pw[r-l]; }
    bool match(int l1, int r1, int l2, int r2) { return hash(l1,r1) == hash(l2,r2); }
};

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << fixed << setprecision(10);

  int n, m; cin >> n >> m;
  string s; cin >> s;
  rolling_hash64 rh(s);

  set<ll> st;
  int l = 0, r = 0;
  for(int i=0;i<m;++i) {
    string q; cin >> q;
    if(q == "L++") {
      l++;
    } else if(q == "L--") {
      l--;
    } else if(q == "R++") {
      r++;
    } else {
      r--;
    }
    st.insert(rh.hash(l, r+1));
  }

  cout << st.size() << endl;
}